Protographic transfer process



Patented Aug. 28, 1923.

warren srarssPATE r OFFICE,

FRANK WILLIAM KENT, OF STREATHABI HILL, LONDON, ENGLAND.

I .PROTOGEAPHIC TRANSFER PROCESS.

No Drawing.

T 0 all to 7mm it may concern,

Be it known that I, FRANK W'ILLIAM KENT, I

a subject of the King of GreatBritain, re; siding at 5 Thornton Avenue, Streatham Hill, in the county of London, England, have invented certain new and useful Iniproveinents in or Relating to l hotographic Transfer Processes, of which the following is a specification. 1

This invention relates to photographic transferprocesses and has for its chief'object to secure a nioreefiective and natural rendering of the sub'ectintensif .ino' the shadows anl throwing; up the high lights in a more efficient manner than has heretofore been obtained in ordinary or transfer hotographic work. a I

iiccording to this invention the transferred print, having a matt or nearly mat-t surface, isprovided lwith'an underlayer or substratum of a reflecting or shiny character lying between the filmpand the paper, card or other mount." The substratum may;

beproduced by the aid of a gelatine adhesive layer soprepared as to give a sheenshowing through the transferred emulsion; The eflect of this shiny under surface is to increase the reflection of light through the parts of,

the print which are not too dense and especially through the parts which represent high lights, with the result that the lighter parts of the print are thrown into much greater relief than is the case with ordinary photographs, while the dark portions' or shadows are intensified, givingan effect which much more closely approaches the.

natural appearance of objects than is. ob-.

tained by any of the usual photographic methods. In the complete print there are three surfaces of reflection,'the upper surface, where the reflection is reduced by the matt eilect, the paper or other mount, and

the surface of contact or union between the back of thetransferredfilm and the underlayer, which reflecting surface lies between the first two. The increase of reflecting power at this intervening su face in, accord ance with the present invention gives the enhanced efiect sought. I A convenient method which may beadopt ed in carrying out this invention 'is'to coat. the paper, card or other mountingmaterial with a solution of gelatine, a suitable strength being about 2%,; per cent or DIOIGOf' gelatine dissolved in hot water, applying the solution rapidly to the mount over a Application filed December 6, 1921. 7 Serial No. 590,243.

sulliciently large area to take the print and as evenly as possible, leaving considerably 'more gelatine than is'required to make the photograph adhere. The card or paper inount'is preferably previously damped or soaked for about a minute or until it becomes limp, in cold water, laid on a 7 surface and the surpluswater removed with a sponge whereupon the gelatine is applied, and the print is also damped or soaked and has its surplus water sponged from it. The print may be prepared with a stripping substratum in accordance with the specification of my prior Application No. 4 l3 l12 but the present process is not confined to any special typeof transfer print excepting. that it must 1 i have 'Inatt or nearly matt shadows after transfer, and be of such a nature that the light can readily pass through it and hereflectedby the backing, to give the required effect. l r

In preparing the transfer print in aceordancewith the method referred to, a hardening agent such as alum, or more es pecially chrome alum, is applied to the base to which theemulsion is applied, solution of the hardening agent, together usually with an anti-greasing agent, such as quillaia bark, is spreadon the base, which maybe a waxed paper base, and is allowed to dry.

The hardening agent, must, of course, be free of any gelatine or other material which,

will allow it to become eflective, and, therefore, use up its hardening properties. The sensitive emulsion is then spread over. the dried substratum and the hardening agent becomes active at the under-surfare of the film so that the .iilm is strengthened and upon transfer the backing can be readily stripped off inthe usual manner.

a T he damp print is then placed face down on the mount, upon the coating of gelatine, the print being. lowered gently down from one edge on to thegelatine surface, any air bubbles and surplus gelatine being squeezed out in the-process of laying down and the sur- 

